Driving mechanism for bobbin shafts of roving frames



June 24, 1930. F. E. BANFiELD,-JR.. AL 1,766,535

v I DRIVING MECHANISM FOR BOBBIN SHAFTS OF ROVING FRAMES Filed Oct. 10, 1928 IN VEN TORS ATTO y Patented June 24, 1930 UNITED STATES PATENT OFFICE FREDERIC E. BANFIELD, JR., AND GEORGE F. ALBRECHT, OF SACO, MAINE, ASSIGNORS T0. SACO-LOWELL SHOPS, OF BOSTON,.MASSACHUSETTS, A CORPORATION OF MAS- SACHUSETTS DRIVING MECHANISM FOR BOBBIN- SHAFTS ROVING FRAMES Application filed. October 10, 1928. Serial No. 311,645

This invention relates to mechanisms for driving the bobbin shafts'of roving frames and similar machines.

These mechanisms usually comprise a series .of spur gears some of which are mounted upon a support which swings up and down in unison with the movement of the bolster rail and bobbin shafts, this mechanism ordinarily being. referred to as a horse head. Aiserious objection to this type of mechanism is the fact that there is a gain or loss in. the speed of the bobbins relatively to that of the spindles and fliers due to the traverse of the bolster rail. Such gain or loss has the effect of varying the stretch or draft of the roving as it is. wound upon the bobbin, thus producing thin or weak places in the roving. Practically all rovings have some variations in thickness and the action just described naturally tends to draw the thin places more than the thicker portions so that the variations are increased.

This condition has long been known and is well recognized in this industry and many attempts have been made to overcome it. The most successful of these developments has been the chain drive which has'had considerable commercial success anddoesovercome the difliculty above described. Such drives, however, are so organized that they are relatively expensive to manufacture. The present invention deals with this problem and it aims to simplify the construction of chain drives and to reduce the expense of manufacturing them.

The nature of the invention will be readily understood from the following description when read in connection with the accompanying drawings and the novel features will be particularly pointed out in the appended claims.

In the drawings,

Figure 1 is a plan view, partly in crosssection, illustrating a mechanism embodying this invention; and

Fig. 2 is a side elevation, partlyin crosssection, of the mechanism shown in Fig 1.

The machine shown comprises a main driving shaft 2 and the usual compound associated with it and operating at a progressively varying speed in the well known manner. A sleeve which forms one element of. this compound is shown at 3 and a driving sprocket wheel l is mounted on the sleeve to rotate with it. The machine also includes a bloster rail 5 and a slide 6 movable with the rail, these parts being mounted for vertical traversing movement in the usual manner. During this movement the slide is guided on a vertical rib 7 which is formed on the end frame piece 8 of the machine.

The bobbins are driven from two parallel horizontal shafts 9 and 10, respectively, which are partly supported in the slide 6 and move up and down in unison with the bolster rail 5. WVhile these shafts drive the bobbins they are usually referred to as the bobbin shafts. Mounted fast on these shafts are sprocket wheels 11 and 12, respectively, which are engaged and driven by a sprocket chain 13. A guide sprocket wheel 14 is mounted on the slide 6 a short'distance above the driven wheel 11 and engages the upper reach of the chain, this Wheel being supported in a bearing block 15 which is mounted in horizontal ways so that it can be adjusted toward or from the driving sprocket wheel 4 to vary the tension on the chain. In order to facilitate this adjustment a thrust screw 16 is arranged to bear against the bearing block 15.

A chain tightening sprocket wheel 17 is arranged to engage the lower reach of the chain 13 and is supported by two links 18 and 19, respectively, which form a toggle. It will be seen from an inspection of Fig. 2 that these two links are pivotally connected together at the axis of the wheel 17 and that the link 18 can also pivot on the bobbin shaft 10, while the other link 19 is mounted to swing on a pivot 20 which is located just below and at the rear of the driving sprocket wheel 4.

Usually the driving sprocket wheel l revolves in a counter-clockwise direction, as seen in Fig. 2, so that the chain travels in the direction indicated by the arrow. Thus the upper reach of the chain is what may be termed the'slack reach, while the lower run of the chain is the taut or drivin reach. In this mechanism, therefore, the tiglitening sprocket wheel 17, contrary to the usual practice, engages the taut reach. Due to the fact, however, that this sprocket wheel is sup rted by a toggle mechanism which compe s it to move in a fixed path, a substantial uniform tension is maintained on the chain at all times. This tension can be varied by adjusting the guide sprocket wheel 14, and while the tension tends to move the sprocket wheel 17 upwardly, or in other words to collapse the toggle, the location of the pivots is such that such an action cannot occur at any point in the traverse of the bolster rail.

It should also be observed that the guide sprocket wheel 1i and the drivin wheel 4: are so located that when the slide 6 is at the lower limit of its traverse the sprocket wheel 14 then is substantially the same distance below the horizontal plane tangent to the upper surface of the wheel 4 that it is above said plane when it is at the upper limit of its traverse. In other words, when the slide is at the middle of its traverse the upper reach of the chain 13 lies in substantially a horizontal plane, the upper edge of the chain at this time being indicated by the dotted line a-b, Fig. 2, and on its up stroke it rises above this plane the same distance that it falls below it on its down stroke. Consequently, the only slack introduoed in the chain by the traversing movement is the very small amount caused by the fact that the guide wheel 14 reciprocates in a straight line instead of swinging in the arc of a circle about the uppermost point on the wheel 4 as a center. Due to this arrangement and the fact that the chain tightening sprocket wheel 17 is definitely controlled at all times by the links 18 and 19, any material gain or loss in the speed of the bobbin shafts is eliminated.

The mechanism is very simple, a single chain only being required, and cams being entirely eliminated. Due to the fact that the chain runs over one of the bobbin shaft pulle s and under the other, it must be provide with driving teeth on both sides, but this does not add materially to the expense of manufacture. Those sprocket wheels sociated with the slide and that part of the chain adjacent to them are enclosed in a casing or guard 21, and an additional guard 22 is bolted to the frame at 23 and protects a considerable part of the upper reach of the chain. Preferably the link 19 is made of channel section so that it forms a guard for a considerable part of the lower reach of the chain.

In locating the positions of the three pivots of the toggle a convenient method of procedure is to assume lengths for the arms 18 and 19 consistent with the space available and the general nature of the design, and to lay out a model or set up the mechanism. It is known that the center of the sprocket wheel 10 will move in a straight line, and the limits of travel of this center are known. With the bobbin rail in its lowest position and the chain taut, the upper end of the arm 1 9 will be free to describe an arc, the scribing point being located in the pivotal center of the arm for this purpose. If the bobbin rail is now raised or the corresponding motion produced in any convenient manner in the model and additional arcs are struck, while still keeping the chain taut, the intersection of these arcs will determine the location for the center of the pivot 20.

lVhile we have herein shown and described a preferred embodiment of our in vention, it will be understood that the invention maybe embodied in other forms without departing from the spirit or scope thereof.

Having thus described our invention, what we desire to claim as new is:

1. In a roving frame orthe like having a compound, the combination of a driving sprocket wheel driven by said compound, two parallel bobbin shafts each provided with a driven sprocket wheel, a slide with which said bobbin shafts are associated, said slide and bobbin shafts being mounted for vertical traversing movement in unison, a guide sprocket wheel mounted on said slide, a chain engaging all of said wheels and driving the bobbin shafts, and a chain tightening sprocket wheel engaging the driving run of said chain, the upper edges of said guide sprocket wheel and said driving sprocket wheel being located in approximately the same horizontal plane when the slide is in the middle of its traverse.

2. In a-roving frame or the like having a compound, the combination of a driving sprocket wheel driven by said compound, two parallel bobbin shafts each provided with a driven sprocket wheel, a slide with which said bobbin shafts are associated, said slide and bobbin shafts being mounted for vertical traversing movement in unison, a guide sprocket wheel mounted on said slide, a chain engaging all of said wheels and driving the bobbin shafts, a chain tightenlng sprocket wheel engaging the driving run of said chain, and two links forming a toggle and supporting said chain tightening sprocket wheel for movement in a fixed path.

3. In a roving frame or the like having a compound, the combination of a drivin sprocket wheel driven by said compoum, two parallel bobbin shafts each provided with a driven sprocket wheel, a slide with which said bobbin shafts are associated, said slide and bobbin shafts being mounted for vertical traversing movementin unison, a

guide sprocket wheel on said slide, a chain tightening sprocket wheel, a chain engaging all of said wheels and driving the bobbin shafts, said guide and driving sprocket Wheels being arranged to support the reach of the chain between them in a substantially horizontal position when the slide is in the middle of the traverse, and links supporting said chain tightening sprocket wheel for movement in a fixed path.

4. In a roving frame or the like having a compound, the combination ofa driving sprocket Wheel driven by said compound, two parallel bobbin shafts each provided with a driven sprocket wheel, a slide with which said bobbin shafts are associated, said slide and bobbin shafts being mounted for vertical traversing movement in unison, a guide sprocket wheel mounted on said slide for adjustment relatively thereto, a chain engaging all of said wheels and driving the bobbin shafts, a chain tightening sprocket wheel engaging the driving run of said chain, said guide sprocket wheel and said driving sprocket wheel being so located that their upper edges lie in approximately the same horizontal plane when the slide is in the middle of its traverse, and two downwardly inclined links supporting said chain tightening sprocket wheel for movement in a fiXed path, said links being pivotally connected together and one being pivoted to said slide and the other being mounted on a stationary pivot located below and behind the axis of said driving sprocket wheel.

5. In a roving frame or the like having a compound, the combination of? a driving sprocket wheel driven by said compound, two parallel bobbin shafts each provided with a driven sprocket wheel, a slide with which said bobbin shafts are associated, said slide and bobbin shafts being mounted for vertical traversing movement in unison, a chain engaging all of said sprocket wheels and driving the bobbin shafts, the sprocket wheels on which said chain runs being arranged to support one reach of the chain in a substantially horizontal position when the slide is in the middle of its traverse, a chain tightening sprocket Wheel engaging said chain, and toggle links supporting said chain tightening sprocket wheel for traversing movement in a substantially fixed path.

In testimony whereof we have hereunto signed our names to this specification.

FREDERIC E. BANFIELD, JR. GEORGE F. ALBRECHT. 

